Sunlight is a source of “renewable” energy that may be captured for human use using various techniques. One method of concentration is to use a number of large parabolic dishes, each of which that supports a mirrored surface that concentrates the light onto its own heat collector fixed relative to the mirrored surface. Each dish is manipulated so that the sunlight stays focused on the collection point as the Earth moves during the day.
Each dish usually has a radius in the order of 10 to 30 meters. The mirrored surface needs to follow a desired parabolic surfaces to a relatively high degree of accuracy so that the focal area is relatively small and the efficiency high.
Prior art techniques of forming the structure of the dish have been to use space frames having nodes with individual struts running between the nodes. The individual node connections and the struts are manufactured to a high dimensional accuracy so that when assembled the resulting dish structure has a high degree of dimensional accuracy.
The problem with prior art space frame designs is that the individual components are relatively expensive to manufacture and so the cost of a dish is, generally, high. This may be acceptable for a one off design, such as a prototype or a radio telescope dish, but the cost is too high for use in a solar thermal power plant that may require hundreds or thousands of individual collector dishes. A further problem is that mirrors cannot easily be mounted directly to the space frame and must be mounted via their own individual support structure. This increases the mass and cost of the overall structure.